From b3dda2fb74ac506a0a2e33087d3b04bb66ea4bc8 Mon Sep 17 00:00:00 2001 From: Andrew Lorimer Date: Fri, 15 Mar 2019 14:53:04 +1100 Subject: [PATCH 1/1] [methods] graphing log functions --- methods/stuff.md | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/methods/stuff.md b/methods/stuff.md index fb94066..bf8fbb0 100644 --- a/methods/stuff.md +++ b/methods/stuff.md @@ -73,7 +73,7 @@ $t$ is time taken $k$ is a constant For continuous growth, $k > 0$ For continuous decay, $k < 0$ -m + ## Graphing expomnential functions $$f(x)=Aa^{k(x-b)} + c, \quad \vert a > 1$$ @@ -85,4 +85,17 @@ $$f(x)=Aa^{k(x-b)} + c, \quad \vert a > 1$$ - dilation of factor $A$ from $x$-axis - dilation of factor $1 \over k$ from $y$-axis +## Graphing logarithmic functions + +$log_e x$ is the inverse of $e^x$ (reflection across $y=x$) + +$$f(x)=A \log_a k(x-b) + c$$ + +where +- **domain** is $(b, \infty)$ +- **range** is $\mathbb{R}^+$ +- **vertical asymptote** at $x=b$ +- $y$-intercept exists if $b<0$ +- dilation of factor $A$ from $x$-axis (reflection across $x$-axis when $A < 0$) +- dilation of factor $1 \over k$ from $y$-axis (reflection across $y$-axis when $k < 0$) -- 2.47.1